Electronic musical instruments, such as electronic organs, are provided with a number of controls for producing different tone effects. For example, many electronic organs have a number of switches which correspond to the musical stops of a pipe organ. Some electronic organs have drawbar controls which are adjusted to produce various tonal effects. The stops, drawbars, or other special effects controls are preset by the musician to produce the desired tonal effects during the playing of a musical number. It is frequently desirable to change the tonal effect by repositioning the controls during the performance of a number. Various systems have been devised for simplifying the resetting of the tone controls so that the musician by changing a single control, can cause the resetting of a large number of associated tone controls. A single actuating control for setting a plurality of tone controls is referred to as a "piston", a term borrowed from pipe organ technology. The piston in the pipe organ provides a way of setting a plurality of stops simultaneously by actuating a single piston. Various types of such combination systems have been provided in the past. In the simplest system a selected set of tone controls is permanently connected to a given piston, so that operation of the piston establishes a predetermined tonal effect which can only be altered by changing the wiring of the controls. A more versatile arrangement is provided by bringing all the wiring out to a plug board or other convenient arrangement for modifying the wiring connections between the piston control and the various tone control switches. More sophisticated and versatile combination systems, referred to as "capture combination systems" are available in which some sort of memory is used which can remember any combination of stops. Each combination can be recalled by actuating a piston which operates to address the location in memory where the particular combination of stops is stored in coded form. The capture combination systems are preferred by the musician because they are the simplest to adjust and offer the most flexibility in performance. However, known capture combination systems are relatively expensive and so are found only on the more expensive electronic musical instruments. Another problem with known capture combination systems is that on the less expansive units there is no visual indication of the setting of the tone controls in response to the operation of a selected piston. Systems have been deviced in which the stop switches or drawbars are mechanically positioned in the same manner as though they had been set by the musician. However, such mechanical setting of the stops and other tone controls adds substantially to the cost of the capture combination system.
An additional problem with such known systems is that the musician must remember the tone control settings that are associated with each piston, so that he will select the correct piston when modifying the tone control settings. One memory technique that has been used is to number the control pistons and then write the piston numbers on the musical score at the bars at which a tone control change is to be made.